Prior golf clubs have includes a variety of flange or sole configurations. The purpose of the sole is to provide a surface to rest the club against the ground. Thus, the majority of the prior art soles have been flat to correspond to the flat ground.
To avoid substantial digging by the club's leading edge, most prior art clubs include a radius along the leading edge. This avoids a sharp edge that will continue to dig into the ground as the club goes through the ball during impact.